DeCure for Mitochondrial complex I deficiency, nuclear type 3
DeCure's autonomous Metabolic AI scientist is researching a drug-repurposing hypothesis for mitochondrial complex I deficiency, nuclear type 3 — screening already-approved drugs against its 1-gene Open Targets disease module to publish open-access research. Research is fast; the path to publication is funded in milestone stages.
Disease moduleMitochondrial complex I deficiency, nuclear type 3 maps to a 1-gene Open Targets module — the target space DeCure's AI scientist screens approved drugs against.
DeCure.ai methodSignature reversal (LINCS) plus network proximity (STRING) rank already-approved drugs likely to perturb this module — the same engine that produces DeCure.ai's repurposing hypotheses.
Repurposing thesisScreening approved medicines against this disease module, then publishing the evidence for the strongest candidate. Known pharmacology and human exposure data make the first question sharper — they do not establish safety or efficacy in a new indication.
Research record
01
ResearchComing soon
Candidate research + dossier — target rationale, drug-repurposing thesis and evidence pack.proof: Published dossier + on-chain hash
02
ValidationComing soon
In-vitro biological validation at a contract research org (CRO).proof: CRO contract + in-vitro report
03
Peer review & paperComing soon
Peer-reviewed paper published open-access (preprint + journal).proof: DOI + open-access link + on-chain hash
Current lead
No approved-drug candidate for mitochondrial complex i deficiency, nuclear type 3 is corroborated in the literature DeepSearch retrieved. Some conditions are managed with non-pharmacological care — a device, surgery or physical therapy — rather than a medicine; that may be the case here, or the literature we found may simply be too sparse yet to support a drug-repurposing angle.
What the evidence adds up to
Mitochondrial complex I deficiency, nuclear type 3, is one of the most common inherited disorders of oxidative phosphorylation, with a birth prevalence of roughly 1 in 5,000 for all OXPHOS disorders. The complex itself consists of 44 subunits, and pathogenic mutations can occur in both nuclear and mitochondrial genes. Despite decades of research, almost half of all complex I deficiencies remain unexplained at the molecular level, and no single gene accounts for more than 5% of cases, indicating that many disease genes have yet to be identified. In a 2022 study of 34 patients with isolated complex I deficiency, screening of six conserved nuclear subunit genes found mutations in only 18% of patients — six individuals. Five of those six had two mutations each, and one had a single mutation in NDUFS4. All six had progressive encephalopathy, and five had Leigh syndrome or a Leigh-like syndrome. Novel mutations were identified in NDUFV1 (R386H, K111E, P252R), NDUFS2 (R221X, M292T, R333Q, IVS9+4A>G), and NDUFS4 (c.221delC). No clear genotype-phenotype correlations emerged.
Cellular and animal models have been developed to study the disease, particularly focusing on the NDUFS4 subunit. These models involve mutations or deletion of the Ndufs4 gene and are used to evaluate potential treatment strategies. However, the review from 2013 notes that the validity of these models for human disease still requires careful assessment. The 2014 review emphasises that many complex I deficiencies are due to defects in genes encoding assembly factors — proteins needed for complex I biogenesis but not part of the final complex — and that more such genes must be identified before definitive genetic counselling can be offered to all affected families.
The clinical presentation is highly variable, including muscle weakness, cardiomyopathy, developmental delay or regression, blindness, seizures, failure to thrive, liver dysfunction, and ataxia. Molecular diagnosis remains challenging because of this heterogeneity and the large number of candidate genes. In a 2011 survey of the literature, 149 patients with isolated complex I deficiency and pathogenic mutations in nuclear genes were described, with 115 different mutations reported across 22 nuclear genes. Missense mutations predominate in core subunits and some assembly factors, while null-type mutations are common in supernumerary subunits and other assembly factors.
What is still missing is a complete genetic picture: many patients never receive a molecular diagnosis, and the unknown genes likely outnumber the known ones. Adequately powered trials of any intervention are absent, and patient stratification by specific genetic defect is not yet possible for the majority of cases. Funding for systematic gene discovery and for the development of stratified, mechanism-based approaches remains insufficient.
Evidence
Retrieved by DeepSearch across 234,678,978 indexed works and resolved on OpenAlex — ranked by citations, including the results that did not work.
Journal of Inherited Metabolic Disease · 2014 · 63 citations · open access
Mitochondrial disease associated with complex I (NADH‐CoQ oxidoreductase) deficiency
AbstractMitochondrial diseases due to a reduced capacity for oxidative phosphorylation were first identified more than 20 years ago, and their incidence is now recognized to be quite significant. In a large proportion of cases the problem can be traced to a complex I (NADH-CoQ oxidoreductase) deficiency (Phenotype MIM #252010). Because the complex consists of 44 subunits, there are many potential targets for pathogenic mutations, both on the nuclear and mitochondrial genomes. Surprisingly, however, almost half of the complex I deficiencies are due to defects in as yet unidentified genes that encode proteins other than the structural proteins of the complex. This review attempts to summarize what we know about the molecular basis of complex I deficiencies: mutations in the known structural genes, and mutations in an increasing number of genes encoding "assembly factors", that is, proteins required for the biogenesis of a functional complex I that are not found in the final complex I. More such genes must be identified before definitive genetic counselling can be applied in all cases of affected families.
Cellular and animal models for mitochondrial complex I deficiency: A focus on the NDUFS4 subunit
AbstractTo allow the rational design of effective treatment strategies for human mitochondrial disorders, a proper understanding of their biochemical and pathophysiological aspects is required. The development and evaluation of these strategies require suitable model systems. In humans, inherited complex I (CI) deficiency is one of the most common deficiencies of the mitochondrial oxidative phosphorylation system. During the last decade, various cellular and animal models of CI deficiency have been presented involving mutations and/or deletion of the Ndufs4 gene, which encodes the NDUFS4 subunit of CI. In this review, we discuss these models and their validity for studying human CI deficiency.
AbstractDisorders of oxidative phosphorylation (OXPHOS) have a birth prevalence of ∼1/5,000 and are the most common inborn errors of metabolism. The most common OXPHOS disorder is complex I deficiency. Patients with complex I deficiency present with variable symptoms, such as muscle weakness, cardiomyopathy, developmental delay or regression, blindness, seizures, failure to thrive, liver dysfunction or ataxia. Molecular diagnosis of patients with complex I deficiency is a challenging task due to the clinical heterogeneity of patients and the large number of candidate disease genes, both nuclear-encoded and mitochondrial DNA (mtDNA)-encoded. In this review, we have thoroughly surveyed the literature to identify 149 patients described with both isolated complex I deficiency and pathogenic mutations within nuclear genes. In total, 115 different pathogenic mutations have been reported in 22 different nuclear genes encoding complex I subunits or assembly factors, highlighting the allelic and locus heterogeneity of this disorder. Missense mutations predominate in genes encoding core subunits and some assembly factors while null-type mutations are common in the genes encoding supernumerary subunits and other assembly factors. Despite developments in molecular technology, many patients do not receive molecular diagnosis and no gene has yet been identified that accounts for more than 5% of cases, suggesting that there are likely many disease genes that await discovery.
[Analysis of UQCRB gene mutation in a child with mitochondrial complex III deficiency].
AbstractOBJECTIVE: To delineate the clinical, biochemical and genetic mutational characteristics of a child with mitochondrial complex III deficiency. METHODS: Clinical information and results of auxiliary examination of the patient were analyzed. Next-generation sequencing of the mitochondrial genome and related nuclear genes was carried out. Suspected mutation was confirmed in both parents with Sanger sequencing. Heterozygous deletion was mapped with chromosomal microarray analysis and confirmed with real-time PCR. RESULTS: The patient presented with vomiting, polypnea, fever, metabolic acidosis, hyperlactatemia, hypoglycemia, dysfunction of coagulation and immune system, in addition with increased lactate dehydrogenase and creatine kinase isoenzyme. Elevation of blood alanine and acylcarnitines as well as urinary ketotic dicarboxylic acid were also noted. The patient also presented development delay, mental retardation and hypotonia. Sequence analysis revealed two mutations in the nuclear gene UQCRB, which included a previously reported frameshift mutation c.306_309delAAAA(p.Arg105Lysfs*22) and a novel large deletion encompassing the entire UQCRB gene. CONCLUSION: The clinical, biochemical and gene mutation characteristics of a child with mitochondrial complex III deficiency caused by mutations of the UQCRB gene have been delineated.
The role of nuclear-encoded subunit genes in mitochondrial complex 1 deficiency
AbstractBACKGROUND: Mitochondrial complex I deficiency often leads to a devastating neurodegenerative disorder of childhood. In most cases, the underlying genetic defect is unknown. Recessive nuclear gene mutations, rather than mitochondrial DNA mutations, account for the majority of cases. AIM: Our aim was to identify the genetic basis of complex I deficiency in 34 patients with isolated complex I deficiency, by studying six of the 39 nuclear encoded complex I subunit genes (NDUFV1, NDUFS1, NDUFS2, NDUFS4, NDUFS7 and NDUFS8). These genes have been conserved throughout evolution and carry out essential aspects of complex I function. METHODS: RNA was extracted from patient fibroblasts and cDNA made by reverse transcription. Overlapping amplicons that together spanned the entire coding area of each gene were amplified by PCR. The genes were screened for mutations using denaturing High Performance Liquid Chromatography (dHPLC). Patient samples with abnormal dHPLC profiles underwent direct DNA sequencing. RESULTS: Novel mutations were identified in six of 34 (18%) patients with isolated complex I deficiency. Five patients had two mutations identified and one patient had a single mutation in NDUFS4 identified. All patients with mutations had a progressive encephalopathy and five out of six had Leigh syndrome or Leigh like syndrome. Mutations were found in three nuclear encoded subunit genes, NDUFV1, NDUFS2 and NDUFS4. Three novel NDUFV1 mutations were identified (R386H, K111E and P252R). The R386H mutation was found in two apparently unrelated patients. Four novel NDUFS2 mutations were identified (R221X, M292T, R333Q and IVS9+4A&ltG). The novel NDUFS4 mutation c.221delC was found in two patients - one in homozygous form and the other heterozygous. Specific genotype and phenotype correlations were not identified. CONCLUSIONS: Nuclear encoded complex I subunit gene mutations are an important contributor to the aetiology of isolated complex I deficiency in childhood. Screening of these genes is an essential part of the investigation of complex I deficiency.
Disease module: DeepOracle (Open Targets). Structures: RDKit from PubChem SMILES. Literature: retrieved by DeepSearch across 234,678,978 indexed works (targeted per-candidate search), resolved on OpenAlex.
DeCure is a research and publication project, not medical advice and not a treatment. "DeCure for X" describes a research goal, not a claim that a cure exists. Backing a cure is a contribution to fund the research — it is not an investment, and confers no yield, royalty, equity or IP ownership. Papers are published open-access by the DeCure.ai DAO.
